Preheat grill or broiler. Trim mushroom
stem ends; cut mushrooms lengthwise in halves. Taking care
not to break caps, thread mushrooms lengthwise on skewers.
To prepare basting sauce: In a small bowl, combine oil,
garlic, salt, and pepper. Brush basting sauce on mushrooms,
peppers, tomatoes, and onion. Arrange skewered mushrooms
and vegetables in a single layer on the grill or broiler
pan rack. Grill on all sides, brushing with more basting
sauce before and after turning; remove each ingredient when
browned and tender, about 10 minutes. Transfer mushrooms
to a bowl. Dice onions and tomatoes; slice jalapeño
peppers; add to bowl. Gently stir in cilantro and lime juice.
Serve warm or at room temperature. Garnish with lime wedges
and cilantro sprigs, if desired. Makes 4 portions.